Exploring the Depths

Scientists document underwater changes in Seychelles waters

Story and photos by The Associated Press

An unprecedented mission to explore the Indian Ocean and record changes taking place beneath the waves began its research in March 2019 in Seychelles waters.

The British-led Nekton Mission arrived off the tiny atoll of Alphonse in the early morning hours, after looming bad weather forced a change of plan and of route.

The ambitious expedition will delve into one of the last major unexplored frontiers on the planet, a vast body of water that’s already feeling the effects of climate change. Understanding the Indian Ocean’s ecosystem is important not just for the species that live in it, but also for an estimated 2.5 billion people at home in the region — from East Africa to the Arabian Peninsula, the Indian subcontinent and Southeast Asia.

Though the mission eventually used high-tech submersibles, research began with more modest equipment: a device to measure the water’s chemistry and a net used to retrieve zooplankton.

“When you actually finally begin doing the science, it’s a bit of a relief and a lot of fun,” said Louise Allcock, a professor of zoology at the University of Ireland in Galway.

Alphonse is a tiny atoll, the tip of a submerged mountain, 232 nautical miles southwest of Seychelles’ capital, Victoria. Within a few kilometers of its shores, the ocean is as deep as 5,000 meters.

Little is known about the biodiversity of Alphonse Atoll because it remains unexplored beyond scuba depth.

Mission member Stephanie Marie, a marine researcher from the Seychelles, recently spent a week on Alphonse working on a study of a fish species called the Giant Trevally, or GT. She said she was excited to find out what’s down there.

“When you have amazing weather, you have a lot of things to see, like the sharks, the GT, the corals also, so it’s like a different place, a different scenery every time,” she said.

Marie’s role is to collect zooplankton to conduct taxonomy identification.

“I’m really excited. It’s going to be eye opening because I’ve never seen so deep,” she said. “It’s really important. Fish feed on zooplankton, so we need to see its quality, because if the ecosystem changes, it may have an impact on the fish we feed on.”

The mission expects to discover new species, as well as document evidence of climate change and of human-driven pollution.

The data will be used to help Seychelles consolidate and expand its policy of protecting almost a third of its national waters by 2020. The sea area to be protected is larger than Germany. The initiative is a key component of Seychelles’ “blue economy,” which attempts to balance development needs with those of the ocean environment.